Specific-gravity meter



v Aug. 24, 1926.

F. F. UEHLING SPECIFIC GRAVITY METER Filed July 15 INVENTOR' H1 gallant 3 Patented Aug. 24, 1926.

UNITED STATES FRITZ FREDERICK ITEHLING, OF PASSAIC, NEW JERSEY.

SPECIFIC-GRAVITY METER.

Application filed July 15, 1925. Serial No. 43,710.

The invention relates to devices for measuring the specific gravity of gases or fluids or for determining the percentage of one gas in a mixture of two gases having different specific gravities.

One form of the invention is illustrated in the accompanying drawings, in which Figure 1 is an elevation, partly in section and partly diagrammatic, illustrating the entire apparatus; Figure 2 represents that portion of the apparatus hereinafter referred to as the vane and its support.

In the particularform of the invention as illustrated, the principal parts of the mechanism are located in a casing or chamber 1. A counter-balanced vane 2 is pivoted within the chamber so that a blade 3, which forms part of said vane, is located between two nozzles 4 and 5, and in a plane at right angles to the axis of these nozzles. Nozzle i communicates with the atmosphere thru pipe 6. The elevation of nozzle 4 may be changed to any point by sliding pipe 6 up or down thru the sleeve or stufiing box 7, and this nozzle can be maintained at any definite elevation by tightening the set screw 8. Nozzle 5 communicates with a gas, the specific gravity of which is to be measured, thru pipe 9, flexible tube 10, and pipe 11. The elevation of nozzle 5 may be changed by moving pipe 9 up or down thru the sleeveor stuffing box 12. This is accomplished by means of the shoulder 13 which 'is permanently fastened to pipe 9, and the screw 14 which is threaded thru the shoulder, and which is held in position by means of the bracket 15 as illustrated. The knurled head 16 which forms part of the screw 14, permits turning the screw in one direction or the other, thus lifting or lowering nozzle 5 as desired.

Art the extreme lower end of the vane 2 and forming part thereof, is attached an electric contact disc 17. An electric contact pin mounted at the end of screw 18 limits the motion of the vane ina counterclockwise direction, due to the obstruction which said pin ofiers to the disc 17. Like wise an electric contact pin at the end of screw 19 limits the motion of the vane in a clockwise direction, due to the obstruction which the pin offers to the disc 17'.

Screws 18 and 19 are respectively thread; ed into brackets 20 and 21 which hold these screws in place. Both brackets are electrically insulated from the casing or chamber 1. i

The vane 2 which is counter-balanced by the counter-weight 22, is supported by frame 23 and is pivoted on bearings as illustrated in Figure 2.

A shaft which carries the pointer 24 is pivoted on and supported by bracket 25. The shaft carries a pinion 26 thru which the pointer 2% is in geared connection with the nozzle 5 by means of the rack 27 and rod 28, which are permanently fastened to pipe 9. By means of this communication, any change in the elevationof nozzle 5 will cause a corresponding change in the position of the pointer 24.

Two electric circuits are provided, one including an electric light bulb 35, and the other including an electric light bulb S7. The first circuit is closed when the electric contact disc 17 touches the electric contact pin at the end of screw 18. The second circuit is closed when the electric contact disc. 17 touches the electric contact pin at the end of screw 19. A battery 29 which is included in both of these circuits is held in place by a spring 30. Spring 30 is supported by a rod 31 and is electrically insulated from casing 1 at The bottom or negative pole of the battery is in electric contact with the casing 1 as illustrated, while the positive pole of the battery is in electric contact with the spring 30, The first circuit includes battery 29, spring 30, wire connection 34, electric light bulb 35, wire connection 36, bracket 20 and screw 18, vane 2 and its component parts, and frame 23 from where the circuit is completed to the bottom of battery 29 thru casing 1. The second electric circuit includes battery 29, spring 30, wire connection 33, electric light bulb 37, wire connection 38, bracket 21 and screw 19, vane 2 and its component parts, and frame 23 from where the circuit is completed to the bottom of battery 29 thru casing 1.

The casing or chamber 1 communicates with an aspirator 39 as illustrated, or with any other means for exhausting the gas from within said chamber. Thus, when the aspirator 39 is in action, a partial vacuum is created within chamber 1. This vacuum in turn causes air to be forced into chamber 1 thru nozzle 1 against one side of blade 3 of the vane. The partial vacuum within chamber l simultaneously causes gas to be forced into the chamber thru nozzle 5 against the opposite side of blade 3 of the vane.- it is obvious that the vane will tend to move in a clockwise or counter-clockwise direction depending upon whether or not the moment of the jet of air from nozzle 4 against blade 3 is greater or less than the moment of the jet of gas from nozzle 5 against blade 3 in the opposite direction. If the moment caused by the jet of air from nozzle is the greater, then the vane will move in a clockwise direction until the contact disc 17 touches the screw 19 which closes the circuit that includes the electric light-bulb 37.

If "on the other hand, the moment caused bythe'jetof gas from nozzle 5 is the greater then the Vane will move in a counter-clocliwise direction until the disc 17 touches the screw 18 which closes the circuit that includes the electric light bulb 35. The electric light bulbs 35 and 37 are of different colors, and for the purpose of this description I have chosen red for the color of bulb 35 and white for the color of bulb '37. It therefore follows that when the red bulb is illuminated, the moment of the .jet of gas from nozzle 5 against the blade 3 is greater than the moment of the jet of air from nozzle 4: against the blade, and conversely when the white bulb is illuminated the moment of the jet of air thru nozzle 4: against the blade 3 is greater than the moment of the jet of gas thru nozzle 5 against the blade. I prefer to use electric light bulbs of different color for determining which of the two circuits is closed, because small electric bulbs,

designed for low voltage and small current consumption, are readily"procurable. The use of such bulbs entirely eliminates any possible objections due to arcing between the electric contact disc 17 and the screws 18 and 19. It is obvious however that numerous other methods for determining which of the two circuits are closed will accomplish the same result.

In the application of my invention for the gmoving body has a definite relation to its mass, or that the force of a jet of any fluid has a definite relation to its specific gravity. By virtue of this law of nature, if the density ofthe gas blowing thru the nozzle 5 against blade 3 increases, then the force of the jet of gas against blade 3 will increase, and likewise if the density of the gas decreases then the force of the jet against the blade 3 will decrease. It is obvious however that the moment of the jet of gas thru nozzle 5 against the blade 3 can be adjusted to any constant quantity, regardless of the density of the gas passing thru the nozzle, by changing the distance of the nozzle from the axis about which the vane is pivoted. This is accomplished, in the particular form of my invention already described, by raising or lowering nozzle 5'by means of screw 14: already referred to. applies to the jet of air from nozzle 4- against the opposite side of the vane. There will however be practically no change in the force of the jet of air thru nozzle 4: due to change in gravity since the density of the atmosphere is practically constant over long periods of time. In addition to the effect on the force of the air or gas issuing from the nozzle 1 or 5, as caused by any change in gravity, the force of the respective jets is of course also affected by the rate of flow thru the nozzles. This rate of flow is however a function of the pressure or partial vacuum within the chamber 1, and any change in the vacuum or pressure within the chamber 1 will affect the flow from nozzle 4: and nozzle 5 in the same proportion. The relative positions of nozzle 5 to balance the effect of one jet against the efiect of the other is therefore independent of'the amount or suction created by the aspirator 39. In other words, if the air entering pipe 6 and the gas entering pipe 11 are at the same temperature andpressure, the relative elevations of nozzles 4 and 5 may be so adjusted 1 that the moment of the jet from one counterbalances the moment of the jet from the other, and this equilibrium will be maintained so long as there is no change in the respective gravities of the gas or air issuing from the nozzles, regardless of any fluctuations of the partial vacuum within the chamber. 7

Although the apparatus as described is primarily a specific gravity meter, 1 have provided a scale L0, as illustrated, which is calibratedso as to determine the percentage of one gas in a mixture of gases, the other constituents of which have a constant mean specific gravity which is less than the gas which is being measured. A concrete ea. ample of such a mixture is a mixture oi carbonic acid. gas and air. For the purpose of illustrating the operation of my inven tion, I am assuming that such a mixture is admitted thru pipe 11, and is pulled into chamber 1 thru flexible connection 10, pipe 9, and nozzle 5, by means of the suction. created by the asp' ator 39. In like manner, and simultaneously, air is being pulled in thru pipe 6 and nozzle 4.

V In order to assure a correct zero reading, it is first necessary to open pipe 11 to the atmosphere, thus admitting air thru both nozzles 4i and Then adjust the elevation of'nozzle 5, by means of the screw 14, to such a point that the pointer 24 coincides with the zero line of scale 40. If, under these conditions,the moment of the jet of air thru n o zzle 4 against one side ofthe The same reasoning blade 3 does not balance the moment of the jet of air from nozzle 5 against the other side of the blade, then the red light 35 or the white light 37 will be illuminated, depending upon whether the electric contact disc 17 is forced against the electric contact screw 18 or 19. In order to adjust the zero reading, pipe 6 including nozzle 1 may be moved up or down, by loosening screw 8, until neither the red light 35, nor the white light 37, is illuminated. When both lights are out, then the electric contact disc 17 will neither touch the screw 18 nor the screw 19, and both the circuit including the red light 35 and the circuit including the white light 37 will be open. Under these conditions the effect of the jet of air from nozzle 1- will exactly balance the effect of the jet of air from nozzle 5, and the apparatus will be adjusted for zero reading. After nozzle 4 has been thus adjusted, it must be permanently fastened in its final position by re tightening the screw 8. Pipe 11 may now be connected with the mixture containing carbonic acid gas. Since such a mixture, which enters at 11, is heaver than air, it will, due to its greater gravity, increase the force of the jet issuing from nozzle 5 against blade 3. This will cause the vane to move in a counter-clockwise direction until the electric circuit including the red light 35 is closed. It is now necessary to again balance the moment caused by the jet of gas from nozzle 5, with the moment caused by the jet of air from nozzle 4;. To accomplish this, nozzle 5 must be lifted by turning the knurled head 16 of the screw 14 until the moment of the jet of gas from nozzle 5 against one side of the vane. again balances the moment of the jet of air from nozzle 4 against the other side of the vane; As soon as this has been accomplished, the electric contact between the disc 17 will be broken and the red bulb will be extinguished.

tion with the pointer 24, will have caused a change in the position of the latter. Since there is a definite position of the pointer 24 for every elevation of the nozzle 5, it is obvious that the scale 40 maybe calibrated to read direct in percentage of carbonic acid gas in the gas mixture flowing thru nozzle 5, the object being to turn the knurled head of screw 14 until neither the red light nor the white light is burning, in which case the pointer will register the correct reading.

In like manner, when the weight of the gas passing thru nozzle 5 decreases, the force of the jet of gas from this nozzle will grow less, and the greater moment ofthe jet of air from nozzle 1 against the blade 8 will cause the contact disc 17 to touch the screw 19, thus closing the electric circuit which includes'the white light37. In :order The new, position of nozzle 5, by virtue of its connecto againdetermine the correctpercentage of carbonic acid gas, the nozzle must be lowered by turning the knurled head of screw lat until the white light has been extinguished, at which time the pointer 24 will again register the correct reading. In this way the pointer 24 can always be made to indicate the percentage ofcarbonic acid gas in the mixture passing thru nozzle 5, by adjusting screw 14 until both lights 35 and 37 are extinguished.

WVhen the apparatus is used to measure the specific gravity of the gas entering nozzle 5, the operation will be exactly the same as above described except that scale 40 would have a different calibration. For gases of specific gravities higher than air, the scale would start with unit-y at a point correspending to zero on scale 40. A reading at this initial line of the scale would indicate that the specific gravity of the gas being measured is equal to that of air. The additional division lines of the scale would represent gravities increasingly higher than unity, up to a point depending upon the range of calibration required. In like manner, when measuring the specific gravity of gases lighter than air, the scale would be calibrated with unity at a point corresponding to the line marked 20 on the illustrated scale. a

In the above description of my invention I have chosen to blow air, or any other gas of constant gravity, against one side of the vane. thru nozzle l, which nozzle may be adjusted to any fixed position by loosening and tightening set screw 8. Against the other side of the vane, I have chosen to blow the gas of variable gravity thru nozzle 5, which nozzle may be moved up or down as required until the effect of the jet issuing therefrom balances the effect of the gas issuing from the fixed nozzle 4. It is obvious however that the fixed nozzle 1 may also be used for the gas of variable gravity, while the movable nozzle 5 is used for the of constant gravity, without in any way interfering with the functioning of my invention. The only difference lies in the fact that when the fixed nozzle 4- is used for the gas of constant gravity,then in order to balance the effect on the vane, nozzle 5 must be moved in one direction for any given change in the gravity of the variable gas passing thru it, while on the other hand, when the movable nozzle 5 is used for the gas of constant gravity, then in order to balance the effect on the vane, nozzle 5 must be moved in the opposite direction for the same change 1n the gravity of the variable gas passing thru the fixed nozzle 4.

In describing my invention with reference to the accompanying illustrations I have as a matter of convenience, referred to changes in the position of the nozzles as changes in their elevation. It is obvious, however, that since the vane is counterbalanced, the entire apparatus may be completely. inverted or placed in any other position without in any way interfering with its operation. My invention may therefore be used on board 01 ships or under any similar conditions with perfect satisfaction.

Although Iliave confined the description and illustrations of my invention to one particular form, it will be obvious that numerous ch ang-es'iii'ay be made in the form of the apparatus described without departing from the spirit oft my invention, and that some features of my inventionmay be used in some cases without the corresponding use of other features.

What I claim as my invention is:

1. In a specific. gravity meter, the co1iibi natioh with a fulcriim', of a vane balanced on the t'iilcruin, means for maintaining a constant monient tending to turn the vane on the fulcrum in one direction, a nozzle thrn which gas or fluid is blown against the vane to create an opposing moment and means for changing the distance of the nozzle from the fulcrum. p

2. In a specific gravity meter, the combination with a vane freeto revolve about a fixed axis, of means for maintaining a constant force against the vane in one, direction, of a nozzle forblowing gas'against the vane in the opposite direction, means for changing the distance of the nozzle 'trom'th'e fixed axis, and means for determining the position of the nozzle. v I V 3. In a specific gravity meter, the combi nation wlth a vane revolvably mountedon a fixed axis, of a nozzle for blowing gas againston-e side of the vane, a second nozzle for blowing gas against the other side of the vane, and means for changing the respective positions of the nozzles.

l. In a specific gravity'me'ter, the combination with a fixed nozzle for blowing gas or fluid in on-e direction, of a movable nozzle I01 blowing gas or fluid in the opposite direction, and a vane located between the two nozzles.

5. In a specific gravity meter, the combination with a counter-balanced vane, of a nozzle, means for blowing gas of constant gravity thru the nozzle against one side ot the vane, a second nozzle, means for blowing gas of a variable gravity thru the second nozzle against the other side of the vane, and means for changing the position of one of the nozzles with respect to the vane.

e. In a specific gravity meter, the combination with an aspirator tor exhaustinggas from a chamber, a vane counter-balanced on aofixed axis within the chamber, a nozzlefor admitting gas of constant gravity against one sideof the vane, a secondnozzle'ior admitting gas of a variable gravity against the other side of the vane, and means' for changing-the relative positions ofthe respec tive nozzles. p 7

7. In a specific gravity meter, the combination with a chamber, of means for ex hausting the gas from the chamber, a-

connte'r-balanced vane pivoted within the chamber, a nozzle for admitting air against one side "of the vane, a second nozzle for ad-' mitting gas a vane, means for changing therelative positions of the, nozzles, and means for measun mg any change mthe relative position of the nozzles.- V I p v v p 8. In a specific gravlty meter, the com-.

bination with a chamhei', bf a fixed nozzle the movable nozzle toward or away from the bearing and'in a plane parallelto the face of the vane, 'means for measuring the motion of themovable 'n'ozzle, 'an'd means for allowing the gas forced thru the. nozzles to escape from the chamber. I 9. In a spe'cific gravity meter, the combination with a chamber, 'ofa counter-bad anced vane pivoted on a fixed within the chamber, means for blowing gas of con stant gravity against one side or the" vane, means for blowing gas o1": variable gravity against the other side of the va1' e, means for balancing the resultant moment of the vane about its axis, and means for exhaust ing the gas which blows against the vane.

V 10. Ina specific gravity meter, the combination with a pivoted vane, of an electric contact medium forming part oft-he vane, a second and a third electricconta ct mediuin between which said first contact medium is free to oscillate, an electric circtiit which is closedwhen the first electric contact niediinii touches the second contact medium, a second electric circuit which is closed when the first electric contact medium touches thethird contact medium, a nozzle for blowing air against one side of the vane, a nozzle electric contact points between which tliil' motion of the vane is restricted, anelectrie cir'cnit which is closed when the vane touches one of the contact points, a second electric circuit which is closed when the vaneltonche's' the other point, an electric light of one color ainst the other sideof the forming part of one of the electric circuits, an electric light of another color forming part of the other electric circuit, a nozzle for admitting gas of constant gravity against one side of the vane, a nozzle for admitting gas of variable gravity against the other side of the vane, means for changing the relative distances of the nozzles from the axis about which the vane is pivoted, and means for registering any change in the relative position of the nozzles.

12. In a specific gravity meter, the com bination with a chamber, of means for can hausting the chamber, a vane pivoted within the chamber, an electric contact pin which limits the motion of the vane in one direction, a second electric contact pin which limits the motion of the vane in the opposite direction, means for adjusting the distance between the two contact pins, an electric circuit which is closed when one of the contact pins touches the vane, .a second electric circuit which is closed when the vane touches the other contact pin, means for determining which of the two circuits is closed, a nozzle for admitting gas of constant gravity against one side of the vane, a nozzle for admitting gas of a variable gravity against the other side of the vane, means for changing the position of one of the nozzles, and a pointer in geared connection with the last mentioned nozzle.

13. In a specific gravity meter, the combination with a chamber, of a vane within the chamber, two pivots on which the vane is balanced, a nozzle on one side of the vane, the axis of which is at right angles to the face of the vane, and thru which the space within the chamber communicates with a gas of a constant gravity, means for adjusting the position of the nozzle relatively to the pivotal axis of the vane, a second nozzle on the other side of the vane, the axis of which is at right angles to the face of the vane, and thru which the space within the chamber communicates with a gas of vari able gravity, means for adjusting the position of the second nozzle relatively to the pivotal axis of the vane, means for exhausting the gas from the chamber, an electric contact pin for limiting the turning of the vane on its pivots in one direction, a second electric contact pin for limiting the turning of the vane on its pivots in the opposite direction, an electric circuit which is closed by contact. between one of the contact pins and the vane, an electric circuit which is closed by contact between the other contact pin and the vane, means for determining when one of the electric circuits is closed, means for determining when the other electric circuit'is closed, a pointer, a connection between the pointer and one of the nozzles for changing the position of the pointer in proportion to any change in the position of the nozzle, and a scale for determining the position of the pointer.

In testimony whereof I hereunto aflix my signature.

FRITZ FREDERICK UEHLING. 

